<!DOCTYPE html>
<html lang="zh-CN">
<head>
    <meta charset="utf-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title>Bootstrap 101 Template</title>
    <link href="../../bootstrap/css/bootstrap.min.css" rel="stylesheet">
    <style type="text/css">
        section {
            margin: 10px;
            outline: 1px solid red;
            padding: 10px;
        }
    </style>
</head>
<body>

<section id="collapse-a">
    <a href="#collapse-sec-1" data-toggle="collapse">折叠</a>
    <article id="collapse-sec-1" class="collapse in">
        <div class="well">折叠内容</div>
    </article>
</section>

<section id="collapse-btn">
    <button data-target="#collapse-sec-2" data-toggle="collapse" class="btn btn-info">折叠</button>
    <article id="collapse-sec-2" class="collapse">
        <div class="well">折叠内容</div>
    </article>
</section>

<section id="collapse-panel">

    <article id="items" class="panel-group">

        <article class="panel panel-default">
            <header class="panel-heading">
                <h4 class="panel-title">
                    <a href="#msg-1" data-parent="#items" data-toggle="collapse">触发器01</a>
                </h4>
            </header>
            <div id="msg-1" class="panel-collapse collapse in">
                <div class="panel-body">第1部分的折叠内容...</div>
            </div>
        </article>

        <article class="panel panel-default">
            <header class="panel-heading">
                <h4 class="panel-title">
                    <a href="#msg-2" data-parent="#items" data-toggle="collapse">触发器02</a>
                </h4>
            </header>
            <div id="msg-2" class="panel-collapse collapse">
                <div class="panel-body">第2部分的折叠内容...</div>
            </div>
        </article>

        <article class="panel panel-default">
            <header class="panel-heading">
                <h4 class="panel-title">
                    <span href="#msg-3" data-parent="#items" data-toggle="collapse">触发器03</span>
                </h4>
            </header>
            <div id="msg-3" class="panel-collapse collapse">
                <div class="panel-body">第3部分的折叠内容...</div>
            </div>
        </article>

    </article>

</section>

<script src="../../jquery/jquery-3.2.1.min.js"></script>
<script src="../../bootstrap/js/bootstrap.min.js"></script>
</body>
</html>